The Study Of Preparation And Properties Of Starch Stearate

Objective:Utilizing less-polluted semidry method to produce stearate corn starch and measured the different testing conditions on the properties of these products,in order to solve the problem of poor hydrophilicity that stearate corn starch possessed,we introduced hydroxypropyl and test the properties changement under various etherification conditions..Methods:(1)Measuring the relationship between substituted ratio of starch stearate and esterifiable time,esterifiable temperature and additive amount of stearic acid according to single factor experiment,subsequently determined the best manufacturing technique according to orthogonal test on the basis of substituted ratio,and determined the relationship between substituted ratio and emulsifying property.(2)Exploring etherified time,etherified temperature,etherified pH and additive amount of etherifying agent on the retrogradation property and emulsifying property of hydroxypropyl starch stearate.(3)Testing whiteness,viscosity,solubility,transparency,retrogradation property of the starches we described above.Results:(1)According to the orthogonal test results,we found the best manufacturing condition was 4% additive amount of stearic acid,esterifiable temperature 145℃,and esterifiable time 4h,under this condition,substituted ratio of starch stearate became highest(0.0055),the emulsifying property of starch stearate increased rapidly with increasing substituted ratio.(2)When etherified temperature achieved 40℃,retrogradation property and emulsifying property of hydroxypropyl starch stearate became best,but the temperature impacted minimumly to emulsion stability;When etherified time processed to 14 h,retrogradation property,emulsifying property and emulsion stability of hydroxypropyl starch stearate became best;With increaseing etherified pH to 12,retrogradation property,emulsifying property and emulsion stability of hydroxypropyl starch stearate elevated gradually,when exceed 12,the properties of hydroxypropyl starch stearate declined slightly;retrogradation property of hydroxypropyl starch stearate became best,when added 8.5% etherifying agent,emulsifying property and emulsion stability declined when added amount exceeded 9%.(3)whiteness 91,viscosity 25 cp,solubility 99.8%,transparency 70%,retrogradation property 58% of starch stearate when substituted ratio achieved 0.0055;whiteness 91,viscosity 25 cp,solubility 100%,transparency 70%,retrogradation property 60% of hydroxypropyl starch stearate when substituted ratio achieved 0.0055.Conclusion:(1)The degree of substitution of stearate corn starch reached 0.0055 under wonderful esterification conditions.(2)The propertes of hydroxypropyl stearate starch were influenced largely by degree of substitution.(3)The properties of stearate starch and hydroxypropyl stearate starch improved evidently with the increasing substituted ratio.